3D - can it be achieve with DV and two projectors? at DVinfo.net

David Delaney · November 11th, 2006, 11:07 PM

I was watching a show on IMAX the other day and they said that 3D needs two projectors, but didn;t go into much detail - just wondering if this is achieveable in the indie field of dv?

Ben Winter · November 11th, 2006, 11:20 PM

Sure--why not? Just mount two DV cameras next to each other and shoot. I believe someone did this with two DVX100's. I did this with an HD10u and a GL2, and used a red-blue effect plugin with glasses and the result was less then spectacular. There was definately some 3D effect, but ultimately I determined the system would have to be designed and used with lots of discretion and exactness in mind, as the images have to line up perfectly, and they can't be perfectly parallel...the sight has to converge at some point, and that point takes a lot of tinkering to get to and relies mostly on what you're going to shoot (mostly closeup stuff, or far away?) Also the HD10u and GL2 have different image qualities completely, so the final result didn't turn out so hot.

Focusing is an issue as well as it's difficult to get both cameras to autofocus to the same thing at the same time. Manual focus is a choice but you obviously can't pull focus at the same time without some kind of designed syncronized focus pull mechanism.

Ultimately it's more difficult than I thought it would be, and your audience won't be seeing it in color unless you do have two projectors with different polarization lenses on them that allow you to project two images at different angles of light, so the polarization glasses work and the audience sees a separate image in each eye.

Cesar Rubio · November 11th, 2006, 11:45 PM

Ben:

I have used a Panasonic DVX-100 & DVC-80 (same camera but without the 24p)
to shoot 3-D stereo and the problems beside what you already mentioned are the lens distance...It has to be 1/30th of the nearest object.

The most used distance between lenses for a normal stereo view (ortho stereo) is 2 1/2 inches or 75mm.(our eyes have this distance more or less)

If you have more distance between lenses like in the Panasonic cameras set-up (13.5mm) then that produces Hyperstereo that makes the objects look like if they were miniature or you are a giant looking at a small world.

The second problem is sync....after a few minutes the cameras start loosing sync by some frames and the longer the take the more noticeable.

Obviously to start the cameras at the same time is another issue but can be corrected in post if you use a slate or a flash at the biggening of each take.

To make good 3-D stereo is a challenge but CAN be obtain if you set your mind to it....in Mexico we have a saying: "if the good things were easy..then anybody(?) could make them..."

3-D has returned and this time is to stay.
James Cameron has sworn that he will never produce a flat (2-D)movie again...

Cesar Rubio.

David MD Smith · November 12th, 2006, 05:06 AM

Interesting stuff!

If you're "just" going to red/green or red/blue (i.e. not going to go down the polarised projecter/glasses route) then you could get away with using just the one camera with the obvious synchronisation benefits. This would invariably involve some ellaborate system comprising mirrors and filters and such like but would save some time in post.

It could be fun to have the between-lens distance vary in the course of a shot. It would be like an extreme dolly/trombone zoom. Weird.

cheers

Dave

David MD Smith · November 12th, 2006, 05:18 AM

You'd probably need a prism too.

There's a lot of potential here.
Just thinking out loud,
It might be the case that you could get away with glasses that are not totally red/blue. I.e. simply tinted, same on the camera filter end. This could alow a degree of colour to be retained. One could then emphasise the amount of 3-d ness through the use of coloured lighting. There is a stills technique whereby the flash and the filter have carefully chosen filters such that only certain objects respond to the flash. I beleive something similar to this was also used in black and white werewolf films during the "tranformation".

David Delaney · November 12th, 2006, 08:36 AM

Ok, did some searching and found more about it here :

http://www.dvinfo.net/conf/showthread.php?t=51074

This guy obviously has some experience and the money to get a couple JCV and DVX's to run tests. Now if only I had those 3d glasses to see his images...

I am thinking that getting two cameras side by side - I guess they have to be pretty close together.

Cesar Rubio · November 12th, 2006, 01:37 PM

Dave:

A system like the one you mentioned already exists:

http://www.berezin.com/3d/nuview.htm

They shoot a documentary named:"Up Denali 3D" with the NuView (http://www.berezin.com/3d/3ddvd.htm) but the stereo effect its NOT true 3-D and shooting with interlaced video cameras have its drawbacks if you are gonna play the video in a PC or for DLP projection set-up (dual or single).

For still photography with a single camera you could use this kit:

http://www.berezin.com/3d/3d_kits.htm

Cesar Rubio.

David Delaney · November 12th, 2006, 01:50 PM

I always thought that 3D works on the idea of focal planes where one camera captures object that are closest and the other camera captures objects that are farther away, thus the 3D?

Cesar Rubio · November 12th, 2006, 01:57 PM

David:

3-D works as OUR eyes do.....each eye (or lens) captures a different view of a scene and then our brain mix the 2 images into one! ...so 3-D has existed since the creation of men!...isn't that amazing?

Cesar Rubio.

David MD Smith · November 12th, 2006, 06:05 PM

Hi All,

Cesar is quite correct on the binocular nature of our ability to view 3d. Essentially each eye has a slightly different view of an object, the brain interprets these to say how far etc etc. E.g if you look at a box a meter or so away, close one eye, then the other, the images observed are distinctly different. Through experience, the brain says its a box a meter or so away. Dosn't always work though.

Cesar, I was thinking about a simpler/simler way to video 3d. The link you gave is very close but, if I understand correctly, involves abusing the two interlaced fields somewhat and synching the viewing glasses. I was going to suggest putting a prism in front of the camcorder lens, with a couple of mirrors left and right each looking through a (blue/red) filter. As such it would be a kind of wysiwyg type of 3d recording, in that the recorded image would be the same as the viewed (with 3d specs) image.

Having said that, I know nothing about 3d video and perhaps even less about prisms.

Cheers

Dave

Cesar Rubio · November 12th, 2006, 09:32 PM

Dave:

You can learn a lot of 3D here:

http://www.stereoscopic.org/index.html

and here:

http://www.3d.curtin.edu.au/

you can download this free books about 3-D stereo:

http://www.stereoscopic.org/library/index.html

I hope this helps.

Cesar Rubio.

November 11th, 2006, 11:07 PM	#1
David Delaney Trustee Join Date: Feb 2006 Location: Niagara Ontario Canada Posts: 1,121	3D - can it be achieve with DV and two projectors? I was watching a show on IMAX the other day and they said that 3D needs two projectors, but didn;t go into much detail - just wondering if this is achieveable in the indie field of dv?

November 11th, 2006, 11:20 PM	#2
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	Sure--why not? Just mount two DV cameras next to each other and shoot. I believe someone did this with two DVX100's. I did this with an HD10u and a GL2, and used a red-blue effect plugin with glasses and the result was less then spectacular. There was definately some 3D effect, but ultimately I determined the system would have to be designed and used with lots of discretion and exactness in mind, as the images have to line up perfectly, and they can't be perfectly parallel...the sight has to converge at some point, and that point takes a lot of tinkering to get to and relies mostly on what you're going to shoot (mostly closeup stuff, or far away?) Also the HD10u and GL2 have different image qualities completely, so the final result didn't turn out so hot. Focusing is an issue as well as it's difficult to get both cameras to autofocus to the same thing at the same time. Manual focus is a choice but you obviously can't pull focus at the same time without some kind of designed syncronized focus pull mechanism. Ultimately it's more difficult than I thought it would be, and your audience won't be seeing it in color unless you do have two projectors with different polarization lenses on them that allow you to project two images at different angles of light, so the polarization glasses work and the audience sees a separate image in each eye. __________________ BenWinter.com

November 11th, 2006, 11:45 PM	#3
Cesar Rubio Regular Crew Join Date: May 2006 Location: Guadalajara, Mexico Posts: 48	Ben: I have used a Panasonic DVX-100 & DVC-80 (same camera but without the 24p) to shoot 3-D stereo and the problems beside what you already mentioned are the lens distance...It has to be 1/30th of the nearest object. The most used distance between lenses for a normal stereo view (ortho stereo) is 2 1/2 inches or 75mm.(our eyes have this distance more or less) If you have more distance between lenses like in the Panasonic cameras set-up (13.5mm) then that produces Hyperstereo that makes the objects look like if they were miniature or you are a giant looking at a small world. The second problem is sync....after a few minutes the cameras start loosing sync by some frames and the longer the take the more noticeable. Obviously to start the cameras at the same time is another issue but can be corrected in post if you use a slate or a flash at the biggening of each take. To make good 3-D stereo is a challenge but CAN be obtain if you set your mind to it....in Mexico we have a saying: "if the good things were easy..then anybody(?) could make them..." 3-D has returned and this time is to stay. James Cameron has sworn that he will never produce a flat (2-D)movie again... Cesar Rubio. __________________ It's the long term experience of problem solving what makes you successful! & what we do in life, echoes in eternity.

November 12th, 2006, 08:36 AM	#6
David Delaney Trustee Join Date: Feb 2006 Location: Niagara Ontario Canada Posts: 1,121	Ok, did some searching and found more about it here : http://www.dvinfo.net/conf/showthread.php?t=51074 This guy obviously has some experience and the money to get a couple JCV and DVX's to run tests. Now if only I had those 3d glasses to see his images... I am thinking that getting two cameras side by side - I guess they have to be pretty close together. Last edited by David Delaney; November 12th, 2006 at 10:24 AM.

November 12th, 2006, 01:37 PM	#7
Cesar Rubio Regular Crew Join Date: May 2006 Location: Guadalajara, Mexico Posts: 48	Dave: A system like the one you mentioned already exists: http://www.berezin.com/3d/nuview.htm They shoot a documentary named:"Up Denali 3D" with the NuView (http://www.berezin.com/3d/3ddvd.htm) but the stereo effect its NOT true 3-D and shooting with interlaced video cameras have its drawbacks if you are gonna play the video in a PC or for DLP projection set-up (dual or single). For still photography with a single camera you could use this kit: http://www.berezin.com/3d/3d_kits.htm Cesar Rubio. __________________ It's the long term experience of problem solving what makes you successful! & what we do in life, echoes in eternity.

November 12th, 2006, 05:06 AM	#4
David MD Smith Regular Crew Join Date: Jan 2006 Location: Oxford, UK Posts: 42	Interesting stuff! If you're "just" going to red/green or red/blue (i.e. not going to go down the polarised projecter/glasses route) then you could get away with using just the one camera with the obvious synchronisation benefits. This would invariably involve some ellaborate system comprising mirrors and filters and such like but would save some time in post. It could be fun to have the between-lens distance vary in the course of a shot. It would be like an extreme dolly/trombone zoom. Weird. cheers Dave

November 12th, 2006, 05:18 AM	#5
David MD Smith Regular Crew Join Date: Jan 2006 Location: Oxford, UK Posts: 42	You'd probably need a prism too. There's a lot of potential here. Just thinking out loud, It might be the case that you could get away with glasses that are not totally red/blue. I.e. simply tinted, same on the camera filter end. This could alow a degree of colour to be retained. One could then emphasise the amount of 3-d ness through the use of coloured lighting. There is a stills technique whereby the flash and the filter have carefully chosen filters such that only certain objects respond to the flash. I beleive something similar to this was also used in black and white werewolf films during the "tranformation".

November 12th, 2006, 01:50 PM	#8
David Delaney Trustee Join Date: Feb 2006 Location: Niagara Ontario Canada Posts: 1,121	I always thought that 3D works on the idea of focal planes where one camera captures object that are closest and the other camera captures objects that are farther away, thus the 3D?

November 12th, 2006, 01:57 PM	#9
Cesar Rubio Regular Crew Join Date: May 2006 Location: Guadalajara, Mexico Posts: 48	David: 3-D works as OUR eyes do.....each eye (or lens) captures a different view of a scene and then our brain mix the 2 images into one! ...so 3-D has existed since the creation of men!...isn't that amazing? Cesar Rubio. __________________ It's the long term experience of problem solving what makes you successful! & what we do in life, echoes in eternity.

November 12th, 2006, 06:05 PM	#10
David MD Smith Regular Crew Join Date: Jan 2006 Location: Oxford, UK Posts: 42	Hi All, Cesar is quite correct on the binocular nature of our ability to view 3d. Essentially each eye has a slightly different view of an object, the brain interprets these to say how far etc etc. E.g if you look at a box a meter or so away, close one eye, then the other, the images observed are distinctly different. Through experience, the brain says its a box a meter or so away. Dosn't always work though. Cesar, I was thinking about a simpler/simler way to video 3d. The link you gave is very close but, if I understand correctly, involves abusing the two interlaced fields somewhat and synching the viewing glasses. I was going to suggest putting a prism in front of the camcorder lens, with a couple of mirrors left and right each looking through a (blue/red) filter. As such it would be a kind of wysiwyg type of 3d recording, in that the recorded image would be the same as the viewed (with 3d specs) image. Having said that, I know nothing about 3d video and perhaps even less about prisms. Cheers Dave

November 12th, 2006, 09:32 PM	#11
Cesar Rubio Regular Crew Join Date: May 2006 Location: Guadalajara, Mexico Posts: 48	Dave: You can learn a lot of 3D here: http://www.stereoscopic.org/index.html and here: http://www.3d.curtin.edu.au/ you can download this free books about 3-D stereo: http://www.stereoscopic.org/library/index.html I hope this helps. Cesar Rubio. __________________ It's the long term experience of problem solving what makes you successful! & what we do in life, echoes in eternity.